Scope and Limitations of Supramolecular Autoregulation

Recently, our group has reported on the ureidopyrimidinone (UPy) induced buffering of 2,7-diamido-1,8-naphthyridine (NaPy) and used this phenomenon to regulate the catalysis of the Michael addition of 2,4-pentanedione to trans-beta-nitro-styrene. We now show that the observed catalytic activity of NaPy is the result of a strong synergy between NaPy and trace amounts of K2CO3, resulting in a more than 100-fold increase in reaction rate compared to the two compounds separately. By keeping the concentration of K2CO3, as well as NaPy, constant, an improved regulation of the catalytic activity is achieved. We show that the catalytic activity can be precisely regulated in a noncovalent manner via the addition of the UPy motif. Finally, different salts and Michael substrates are screened to assess the selectivity of this catalytic couple and to provide a platform for future research in molecular buffering, regulation, and chemical networks.